Spray tube



w. LEUPOLD Jan. 15, 1935.

SPRAY TUBE Filed July 1, 1932 Y //7 venzon' WALTER LEUPOLD ,MWCz Attorneys Patented Jan. 15, 1935 UNITED STATES 1,987,962 SPRAY TUBE Walter Leupold,

Mannheim-Waldhof, Germany,

assignor of one-half to Zellstofffabrik Waldhof, Mannheim-Waldhof, Germany, a, joint-stock company of Germany Application July 1, 1932, Serial No. 620,398 In Germany July 4, 1931 6 Claims.

This invention refers to a spray tube for producing an unbroken uniform curtain of liquid, consisting of water, or of a solution of, for example, colouring matter, chemicals, etc., and which 6 can be used for treating substances of all kinds as, for example, fibrous or powdered material. With spray tubes of this type one of the principal requirements is that the water or solution should act uniformly on the material being treated.

Methods are already known whereby the liquids or solutions are applied to the material being treated in the form of individual jets of liquid, or a spray of small drops, but hitherto it has not been possible to apply the liquid uniformly to all parts, and to avoid damaging the material being treated such, for example, as a fibrous material.

According to this invention it becomes possible to obtain an unbroken uniform curtain of liquid by means of a spray tube, by arranging a strainer tube in between the perforated supply tube and an outer cover tube having a longitudinal slot.

The distance between the supply tube and the strainer tube on the one hand, and between the strainer tube and the cover tube on the other hand, may suitably be some 5 50 mm., depending on the length of the tube system and the quantity of liquid to be sprayed.

In order evenly to reduce the varying outlet pressure of the liquid in the supply tube, and to avoid disturbing the formation of the uniform curtain of liquid in the slot of the cover tube, it is advantageous to arrange the longitudinal slot in the cover tube diametrically opposite the perforations in the supply tube. One or more rows of holes may be provided in the supply tube. It is an advantage, however, so to proportion the total cross sectional area of the holes in the supply tube that its maximum value corresponds approximately to the cross sectional area of the supply tube.

The variable outlet pressure of the liquid can be still further smoothed by arranging that the area of the holes in the supply tube increases in the direction of flow, corresponding to the reduction in directional pressure and momentum or movement of the liquid. This can be done either by letting the area of the individual holes increase in the direction of fiow, or by increasing the number of holes in the direction of flow.

A constructional example of the subject of this invention is shown in the drawing as follows:-

Figure 1. A general view of the spray tube.

Figure 2. A longitudinal section. Figure 3. A cross section.

The liquid supply tube B is provided with rows of holes F on its upper side. The size of the holes in the supply tube is determined according to the length of the tube and the quantity of fluid to be passed through. For example, openings of 0.5-2 mm. may be used. The supply tube B is surrounded at a certain distance by the strainer tube C which again is surrounded at a certain distance by the cover tube A, which has a longitudinal slot D on its lower side. The strainer and cover tubes are attached to the supply tube by means of distance rings and screwing at one end. If the liquid enters at one end only the other end of the supply tube is closed up.

An example of the use of this new spray tube is the treatment of the travelling sheet of paper on the wire of a paper machine'by a curtain of liquid for the purpose of washing, colouring, heating etc. without affecting the texture of the material.

What I claim and desire tosecure by Letters Patent of the United States is:-

1. A spray tube for producing an unbroken, smooth and uniform curtain of liquid, including the combination, with a perforate supply pipe supplying a plurality of directional jets of the liquid, of an outer covering pipe having a longitudinal slot disposed out of register with the perforations in said supply pipe and through which the liquid may ultimately issue to form said ourtain, and a perforate screen surrounding the perforate supply pipe and interposed between the perforations therein and the covering pipe in order to equalize the directional tendency and momentum of the jets of said liquid flowing from the perforations in said supply pipe toward said longitudinal slot in said covering pipe.

2. A spray tube according to *claim 1, wherein the sum total area of the perforations of the perforated supply pipe is substantially balanced and equalled by the cross sectional area of the longitudinal slot in the outer covering pipe.

3. A spray tube according to claim 1, wherein the perforations of the perforated supply pipe are arranged in one or more longitudinal rows disposed diametrically opposite to the longitudinal slot in the outer covering pipe, in order to produce a maximum smoothing and equalizing of the directional jets issuing from the perforations of said supply pipe.

4. A spray tube according to claim 1, wherein the sum total area of the perforations of the and uniform curtain of flowing liquid, compris ing the combination of a perforated hollow supply member having the perforations thereof disposed in a row, an outlet member spaced from and surrounding said supply member and having a longitudinal slot out of register with the row of perforations in said supply member, through which longitudinal slot the liquid ultimately issues to form said curtain, and a perforate cylindrical screen surrounding said perforated supply member and interposed between the row of perforations therein and the longitudinal slot in the outlet member, in order to equalize the currents of liquid flowing from said perforations toward said longitudinal slot.

; WALTER LEUPOLD. 

